JPH0451218Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a fluid coupling that utilizes the shear resistance of viscous fluid.

Prior Art In recent years, this type of fluid coupling, which is suitable for use in drive devices of cooling fan devices for internal combustion engines for vehicles, has been developed that can change the rotational speed of the cooling fan device in three stages depending on the heat generation status of the engine. , improved fluid couplings have been proposed (for example, Japanese Patent Application Laid-Open No. 61-136026
Publication No.).

This type of conventional example shown in FIG. 33 is first opened, and then the inner communication hole 34 provided radially inward is opened together with the outer communication hole 33, whereby the working fluid chamber is sequentially opened from the storage chamber 35 through the outer communication hole 33 and the inner communication hole 34. Partition plate 3 in 36
A minute gap 38 formed between 2 and the wheel 37
The amount of working fluid filled in is increased in three stages, using the fluid in this minute gap 38 as a medium,
The rotation of the input side drive shaft 39 is caused by the rotation of the input side drive shaft 39 to the output side body 40.
It is transmitted in stages. On the other hand, when the ambient temperature decreases, contrary to the above case, the amount of working fluid filled in the minute gap 38 in the working fluid chamber 36 is reduced in three stages, thereby reducing the output. The rotational speed of the side body 40 can be reduced in three stages. That is, the rotational speed of the output side body 40 is changed in three stages, and a cooling fan device (not shown) connected to the output side body 40 is rotated at each speed.

Problems to be solved by the invention In the conventional technology configured as above,
Since the minute gap 38 is configured to be formed between the wheel 37 and the partition plate 32, the partition plate 3
A labyrinth protrusion 42 that is combined with a labyrinth protrusion 41 of the wheel 37 must be formed on the side facing the wheel 37 of No. 2. Therefore, after forming the partition plate 32 thickly using aluminum die-casting or the like, the labyrinth protrusion 4
There was a problem that the second part had to be machined, which required a large number of processing steps and increased manufacturing costs.
Therefore, an object of the present invention is to provide a fluid coupling that can solve the problems of these conventional techniques.

Means for Solving the Problems That is, the fluid coupling of the present invention includes a body rotatably fitted to the input drive shaft, and a cover fixed to the body and forming an annular space between the body and the body. a partition plate fixed to the cover and separating the annular space into a working fluid chamber and a storage chamber; a partition plate fixed to the input side drive shaft and rotatably housed in the working fluid chamber; A fluid coupling comprising a substantially disc-shaped wheel forming a minute gap between the cover and the cover, the minute gap consisting of a radially outer part and a radially inner part, and the diameter of the minute gap is A first communication passage for supplying the working fluid in the storage chamber to the outer part in the direction is provided across the partition plate and the cover, and a second communication passage for supplying the working fluid in the storage chamber to the inner part in the radial direction of the minute gap.
A communication passage is formed in the partition plate, and a temperature-sensitive valve that opens the first communication passage first among the first communication passage and the second communication passage is arranged adjacent to the partition plate. A return path is formed in the cover for returning fluid to the storage chamber.

Function According to the fluid coupling of the present invention, when the ambient temperature is low, the temperature-sensitive valve blocks the flow of the working fluid from the storage chamber to the working fluid chamber. Therefore, only a very small amount of working fluid remains in the small gap, and the difference in rotational speed between the wheel and the cover (body) increases, and even when the wheel rotates, the cover (body) only rotates at a low speed. Yes (low speed range). When the ambient temperature rises, the first communication passage is opened by the temperature-sensitive valve, and the working fluid is supplied from the storage chamber to the radially outer portion of the minute gap. Therefore, the cover (body) rotates in the same direction as the wheel while slipping relative to the wheel due to the shear resistance of the working fluid supplied to the radially outer part of the microspace (medium speed range). When the ambient temperature further rises, the second communication passage is also opened by the temperature-sensitive valve, and the working fluid is also supplied from the storage chamber to the radially inner part of the minute space. Therefore, the working fluid is filled over the entire small gap, and due to the large shear resistance generated in the working fluid, the difference in rotational speed between the two becomes the smallest, and the cover (body) rotates approximately in synchronization with the wheel (high-speed range ). The working fluid flowing from the inside to the outside in the radial direction through the minute gap is pumped by the pump action of the pump section provided on the outer circumferential side of the working fluid chamber, and is returned to the storage chamber through the return path 15. .

On the other hand, when the ambient temperature drops, contrary to the above case, the working fluid that is filled in the minute gap in the working fluid chamber is reduced in three stages, thereby preventing the rotation of the cover (body). The speed is reduced in three stages.

Example Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view showing one embodiment of the fluid coupling of the present invention. In the figure, 1 is an input drive shaft connected to an engine auxiliary pulley (not shown); A substantially dish-shaped body 3 is rotatably fitted in the body 3 via a bearing 2. A substantially dish-shaped cover 5 having a boss portion 4 in the center is fixed to one side of the body 3.
An annular space 6 is formed between the body 3 and the body 3. A plurality of annular labyrinth protrusions 7 are formed on the side surface of the cover 5 facing the annular space 6 from radially inward to radially outward. Reference numeral 8 denotes a substantially disk-shaped partition plate press-formed from a thin steel plate.The outer peripheral end of this partition plate 8 is fixed to the cover 5, and the annular space 6 is connected to the working fluid chamber 9.
It is divided into two rooms: a storage room 10 and a storage room 10. Reference numeral 11 denotes a substantially disc-shaped wheel whose inner periphery is fixed to the input drive shaft 1, and this wheel 11 is rotatably housed in the working fluid chamber 9. A cover 5 is provided on the side surface of the wheel 11 facing the cover 5.
A labyrinth protrusion 13 is integrally formed with the labyrinth protrusion 7 formed in the labyrinth protrusion 7 to form a minute gap 12 extending from radially inward to radially outward. Further, on the outer circumferential portion of the working fluid chamber 9, a pump portion 14 is provided, which is mainly constituted by a protrusion approaching the outer end of the wheel 11, and exerts a pumping action by rotation of the wheel 11. A minute gap 12 is formed by combining the labyrinth protrusions 7 and 13 of the cover 5 and the wheel 11.
2a, a radially outer portion 12b, and an annular passage 12c formed between these two portions.
Reference numeral 15 denotes a reflux path formed in the cover 5, and this reflux path 15 allows the working fluid pumped by the pump section 14 to flow back from the working fluid chamber 9 to the storage chamber 10, and one end is located closer than the labyrinth protrusion 13. It opens at the side surface on the radially outer working fluid chamber 9 side, and the other end opens into the storage chamber 10 . Reference numeral 16 denotes a first outflow port formed in the partition plate 8, and a sub-first outflow port 17 is formed at a position radially outward adjacent to the first outflow port 16. Reference numeral 18 denotes a working fluid supply passage formed in the cover 5. One end of this working fluid supply passage 18 opens at a portion corresponding to the sub-first outlet 17, and the other end opens at a portion radially outward of the minute gap 12. 12b, preferably annular passage 12
It opens at c. Reference numeral 19 denotes a guide cap fixed to the side surface of the partition plate 8 on the side of the working fluid chamber 9, and this guide cap 19 is connected to the first outlet 1.
6 and the sub-first outlet 17 so as to communicate with each other,
The working fluid flowing out from the first outlet 16 is guided to the sub-first outlet 17. A first communication path 20 communicates between the storage chamber 10 and the radially outer portion 12b of the minute gap 12 through the first outflow port 16, the sub-first outflow port 17, the guide cap 19, and the working fluid supply path 18. It consists of Reference numeral 21 denotes a second communication passage formed in the partition plate 8, and as shown in FIG. An opening is formed at the position where the storage chamber 1 is located.
0 and the working fluid chamber 9 are communicated with each other. 22 is the partition plate 8
This temperature-sensitive valve 22 includes a plate-shaped valve body 22a disposed adjacent to the side surface of the partition plate 8 on the storage chamber 10 side, and a valve body 22a that covers the valve body 22a. The spiral bimetal 22c is rotated via a center pin 22b pivotally supported by the boss portion 4 of 5, and the first outlet 16 (first communication path 20) and the second The communication passage 21 is opened and closed to control the flow of the working fluid flowing out from the storage chamber 10 to the working fluid chamber 9 . Note that the spiral bimetal 22c of the temperature-sensitive valve 22
The outer peripheral end 23 is fixed to the cover 5, and the inner peripheral end 24 is fixed to one end of the center pin 22b. Further, 25 is an air vent hole bored approximately in the center of the partition plate 8. 26 is a guide groove formed at a position corresponding to the opening end of the return passage 15 on the working fluid chamber 9 side of the cover 5;
guides the working fluid pumped by the pump action of the pump section 14 to the reflux path 15 .

According to the above embodiment structure, when the ambient temperature is low, the first outlet 16 formed in the partition plate 8
(The first communication path 20) and the second communication path 21 are closed by the temperature-sensitive valve 22, and the flow of the working fluid from the storage chamber 10 to the working fluid chamber 9 is blocked. Here, the torque transmitted to the cover 5 (body 3) depends on the amount of working fluid within the working fluid chamber 9, specifically within the minute gap 12. Therefore, the working fluid chamber 9
When the supply of working fluid to the inside is cut off, the minute gap 1
Since only a very small amount of working fluid remains in the wheel 11 and the cover 5 (body 3).
The rotational speed difference between wheel 11 and
Even if the cover 5 (body 3) rotates, the cover 5 (body 3) only rotates at a low speed (low speed range). When the ambient temperature rises, the bimetal 22c of the temperature-sensitive valve 22 responds to this, and this bimetal 22c rotates the valve body 22a clockwise in FIG. 2 via the center pin 22b, and first the first outlet 16 (First communication path 2
Open 0). As a result, the working fluid in the storage chamber 10 passes through the first communication path 20 and passes through the minute gap 1.
It is supplied into the radially outer portion 12b of No. 2. The working fluid supplied to the radially outer portion 12b of the minute gap 12 flows radially outward within the minute gap 12 due to the centrifugal force caused by the rotation of the wheel 11. At this time, the torque of the input drive shaft 1 is transmitted to the cover 5 (body 3) due to the shear resistance of the working fluid according to the amount of working fluid in the minute gap 12, but at this time the working fluid is supplied. is a part of the minute gap 12, that is, the minute gap 12
Since it is only the radially outer portion 12b of the cover 5
rotates with slippage relative to the wheel 11 (medium speed range). As the ambient temperature rises further,
The bimetal 22c of the temperature-sensitive valve 22 further rotates the valve body 22a clockwise via the center pin 22b to open the second communication passage 21 (see FIG. 2). Therefore, the working fluid in the storage chamber 10 is sufficiently supplied to the radially inner portion 12a of the minute gap 12. As a result, the torque of the input side drive shaft 1 is sufficiently transmitted to the cover 5 (body 3), the rotational speed difference between the two is minimized, and the cover 5 (body 3) is almost synchronized with the wheel 11. Rotates (high speed range). The working fluid flowing from the inside to the outside in the radial direction within the minute gap 12 is pumped by the pumping action of the pump section 14 provided on the outer periphery of the working fluid 9, and is stored through the return path 15. It is refluxed to chamber 9. In this way, when the ambient temperature rises, the rotation speed of the cover is increased in three steps.

On the other hand, when the ambient temperature decreases, contrary to the above case, the amount of working fluid filled in the minute gap 12 in the working fluid chamber 9 is reduced in three stages, thereby As a result, the rotational speed of the cover 5 (body 3) is reduced in three steps.

As described above, according to the present embodiment, the rotation speed of the cover 5 (body 3) is set in three stages depending on the ambient temperature, that is, the working fluid is spread over the entire region from the storage chamber 10 to the minute gap 12 of the working fluid chamber. a high speed range in which the cover 5 rotates in substantially synchronization with the wheel 11, a low speed range in which substantially the entire amount of working fluid is recovered from the working fluid chamber 9 into the storage chamber 10, and thereby substantially stopped; The speed can be appropriately selected from three stages including the intermediate speed.

Effects of the Invention As described above, in the present invention, since a minute gap is formed between the cover and the wheel, the partition plate can be processed by press molding. Therefore,
Compared to conventional technology, in which the labyrinth protrusions had to be machined after the partition plate was molded with aluminum die-casting, the number of processing steps can be significantly reduced, and manufacturing costs could be reduced. Ta. In addition, a first communicating passage for supplying the working fluid in the storage chamber to the radially outer part of the minute gap is provided across the partition plate and the cover, and the first communicating passage supplies the working fluid in the storage chamber to the radially inner part of the minute gap. A second communication passage for supplying the fluid is formed in the partition plate, and a temperature-sensitive valve that opens the first communication passage first among the first communication passage and the second communication passage is arranged adjacent to the partition plate, while the temperature-sensitive valve opens the first communication passage first. Since the cover is formed with a return path that returns the working fluid in the fluid chamber to the storage chamber, the relative rotational speed of the cover (output side) relative to the cover (input side) can be controlled depending on the ambient temperature, similar to the conventional technology. Not only can it be changed into three stages, but it also has a great practical effect in that it can provide inexpensive products.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a fluid coupling showing an embodiment of the present invention, FIG. 2 is a view taken in the direction of arrow A in FIG. 1, and FIG. 3 is a sectional view of a conventional fluid coupling. DESCRIPTION OF SYMBOLS 1... Input side drive shaft, 3... Body, 5... Cover, 6... Annular space, 8... Partition plate, 9... Working fluid chamber, 10... Storage chamber, 11... Wheel,
12...Small gap, 12a...Radially inner part, 1
2b...Radially outer part, 14...Pump part, 15
...reflux path, 20...first communication path, 21...second
Communication path, 22...temperature-sensitive valve.

Claims (1)

[Scope of utility model registration request] a body rotatably fitted to the input side drive shaft; a cover fixed to the body and forming an annular space between the body; and a cover fixed to the cover to define the annular space as a working fluid chamber and storage. a partition plate separated from the chamber; and a substantially disc-shaped wheel fixed to the input drive shaft, rotatably housed in the working fluid chamber, and forming a small gap between the wheel and the cover. A fluid coupling comprising: a first communication path in which the minute gap is composed of a radially outer part and a radially inner part, and a working fluid in the storage chamber is supplied to the radially outer part of the minute gap; A second communication passage is formed in the partition plate and is disposed astride the partition plate and the cover, and supplies the working fluid in the storage chamber to the radially inner part of the minute gap, and the first communication passage and the second communication passage are formed in the partition plate. A temperature-sensitive valve that opens the first communicating passage first among the two communicating passages is arranged adjacent to the partition plate, and a return passage that returns the working fluid in the working fluid chamber to the storage chamber is formed in the cover. A fluid coupling characterized by: